ASHRAE 62.2

ASHRAE 62.1 / Crestline BAS Specification

This CO2 sensor installation meets all requirements. The 0-2000 ppm range covers the full operating range needed for DCV (outdoor ambient of ~420 ppm to maximum occupied levels around 1000-1200 ppm). The ±30 ppm accuracy meets the specification tolerance. Mounting at 4 feet (breathing zone height) on an interior wall away from supply diffusers and doors ensures the sensor reads representative room air rather than being influenced by drafts or supply air.

ASHRAE 62.1 / ISO 14644-4

Clean room ductwork must NOT have internal fibrous liner. Fibers shed into the airstream and contaminate the clean space. Use smooth galvanized or stainless steel duct.

ASHRAE 62.1 Section 5.9 / OSHA 1910.94

Industrial exhaust systems require adequate makeup air to replace the exhausted volume. A closed makeup air damper creates negative building pressure, reducing exhaust hood capture velocity and potentially causing backdrafting of combustion appliances. ASHRAE 62.1 and OSHA require balanced ventilation in industrial facilities.

ASHRAE 90.1 — Insulation

Chilled water pipes MUST have vapor barrier on insulation to prevent condensation. Without it, moisture penetrates insulation, causes mold, and reduces R-value to near zero.

ASHRAE 90.1 / ASME B31.9

Chilled water piping insulation must have a continuous vapor barrier (vapor retarder) on the exterior to prevent moisture from migrating through the insulation and condensing on the cold pipe surface.

ASHRAE 90.1 / IECC

Economizer operation using outdoor air for free cooling is not only allowed but required by energy codes for most commercial systems. Using enthalpy (temperature + humidity) control is the preferred method. The 55°F changeover and 100% OA capability are standard economizer settings. The 20% minimum OA ensures ventilation is always maintained.